Eating dinner early associated with lower risk of breast and prostate cancers

Recently, the International Journal of Cancer published the study “Effect of mistimed eating patterns on breast and prostate cancer risk (MCC-Spain study)” looking at whether eating and sleeping times could be related to the risk of suffering breast and prostate cancer, with the participation of Pilar Amiano from the Gipuzkoa Sub-Office of Public Health and member of the Biodonostia HRI research area in Epidemiology and Public Health.

People who dine early or go to sleep at least two hours after having dinner have a 20% lower chance of suffering breast and prostate cancer with respect to those who go to bed directly after having eaten their last meal of the day. This is the main conclusion of the MCC-Spain study which has, for the first time, analysed the relationship between dinner and sleeping times and the risk of cancer in people.

Until now, studies carried out on people in relation to food and cancer had focussed on dietary patterns. An analysis had been made, for example, of whether people eat red meat, fruit or vegetables, and comparisons had been drawn between food quantity and obesity. However, no account had been taken of other factors surrounding a daily action as prevalent as eating: the time of consuming food and the activities carried out before and afterwards. Recent evidence in experimental studies shows that eating times are important and that eating late affects the health.

The objective of this study, published in the International Journal of Cancer, was to evaluate whether eating and sleeping times could be related to the risk of suffering breast and prostate cancer – two of the most common cancers worldwide and which are more closely related to night work and to the circadian disruption or alteration of our biological clock. The study therefore took account of each person’s living habits and chronotype, an individual attribute related to their preference for day or night-time activities.

In the framework of the MCC-Spain project, data were evaluated corresponding to 621 cases of prostate cancer and 1,205 of breast cancer, and to 872 men and 1,321 women randomly chosen at primary healthcare centres. The participants came from different parts of Spain. The analysis was made based on data collected during interviews regarding their eating and sleeping times, their chronotype and a questionnaire on eating habits and to what extent they follow the recommendations for preventing cancer.

The study concludes that following daytime eating patterns is associated to a lower risk of cancer. The results also highlight the importance of taking account of the circadian rhythm in studies on diet and cancer.

If the results are confirmed, they will have implications on cancer prevention recommendations, which do not currently take account of eating times. This would have particular repercussion in cultures such as those of southern Europe, where dinner is eaten late.